A claim can take a year or more to resolve, and in a serious case considerably longer. Waiting until then for treatment is often the wrong answer, because early rehabilitation tends to produce better recovery than treatment delayed. There are mechanisms designed to avoid that wait, and they are worth asking about.
Where liability is admitted, or where the insurer accepts responsibility in principle, it is sometimes possible to arrange physiotherapy, occupational therapy or psychological support early, with the cost met by the insurer. Some insurers positively prefer this, because it is usually cheaper for them than a longer recovery. Where liability is disputed, the position is harder, but it is not always impossible.
A related route is the interim payment, which is money paid on account of compensation before the claim settles. It can be used to fund treatment, rehabilitation, care or equipment while the claim continues. Interim payments usually require an admission of liability or a court order and are not available in every case, but where they can be obtained they make a real practical difference.
We cannot promise privately funded treatment in every case, and it would be wrong to suggest otherwise. What we can do is raise it early, put the request to the insurer properly, and explain honestly what is and is not achievable in your circumstances.